420 Practical hints
Jump starting
Make sure the two vehicles do not 
touch.
Turn off all electrical consumers.
Apply the parking brake (page 59).
Make sure the gear selector lever* is 
set to positionP (manual transmission 
to Neutral).
Open the hood (page 294).
Flip up cover from positive under hood 
terminal2 in front of water tray1 
(
page 416).1Positive terminal of charged battery
2Positive terminal
3Negative terminal of charged battery
4Negative terminal
Connect positive terminal1 of the 
charged battery with positive 
under-hood terminal2 in front of the 
water tray with one jumper cable. 
Clamp the cable to positive terminal1 
of the charged battery first.
Start the engine of the vehicle with the 
charged battery and run at idle speed.
Connect negative terminal3 of the 
charged battery with negative 
under-hood terminal4 with the 
second jumper cable. Clamp the cable 
to negative terminal3 of the charged 
battery first.
Start the engine of the disabled 
vehicle.
You can now turn on the electrical 
consumers. Do not switch on the 
headlamps under any circumstances.
Remove the jumper cables first from 
negative terminals3 and4 and then 
from positive terminals2 and1.
You can now switch on the headlamps.
Have the battery checked at the 
nearest authorized Mercedes-Benz 
Center.
Warning!G
Keep flames or sparks away from battery. 
Do not smoke. 
Observe all safety instructions and precau-
tions when handling automotive batteries 
(
page 303).
!Never invert the terminal connections.